U.S. patent application number 11/519289 was filed with the patent office on 2007-03-15 for image forming apparatus.
This patent application is currently assigned to Sharp Kabushiki Kaisha. Invention is credited to Hirokazu Izumi, Hisaaki Kobayashi, Hideyuki Nishimura, Hirofumi Sakita.
Application Number | 20070058997 11/519289 |
Document ID | / |
Family ID | 37496883 |
Filed Date | 2007-03-15 |
United States Patent
Application |
20070058997 |
Kind Code |
A1 |
Sakita; Hirofumi ; et
al. |
March 15, 2007 |
Image forming apparatus
Abstract
An image forming apparatus is provided, which is capable of
using such a toner cartridge preferentially without interrupting an
image forming action as is desired for an early use and as has a
less toner remaining amount. When a toner density in a developer
container to be supplied with the toner from either of two toner
cartridges becomes low, a control section drives either of motors
in response to toner remaining amount detection information which
is information on the remaining amount of the toner contained in
each of the toner cartridges, so that the toner may be supplied
from the toner cartridge having the less toner remaining amount.
Thus, the toner can be supplied to the developer container from the
toner cartridge having the less toner remaining amount.
Inventors: |
Sakita; Hirofumi; (Nara,
JP) ; Nishimura; Hideyuki; (Osaka, JP) ;
Kobayashi; Hisaaki; (Nara, JP) ; Izumi; Hirokazu;
(Nara, JP) |
Correspondence
Address: |
EDWARDS & ANGELL, LLP
P.O. BOX 55874
BOSTON
MA
02205
US
|
Assignee: |
Sharp Kabushiki Kaisha
Osaka
JP
|
Family ID: |
37496883 |
Appl. No.: |
11/519289 |
Filed: |
September 11, 2006 |
Current U.S.
Class: |
399/27 |
Current CPC
Class: |
G03G 2215/0695 20130101;
G03G 2215/0888 20130101; G03G 15/0872 20130101; G03G 15/0858
20130101; G03G 2215/0697 20130101; G03G 15/0856 20130101 |
Class at
Publication: |
399/027 |
International
Class: |
G03G 15/08 20060101
G03G015/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 12, 2005 |
JP |
P2005-264090 |
Claims
1. An image forming apparatus comprising: a developing section for
developing with toner contained in a developer container; a
plurality of toner cartridges for containing toners of an identical
color; a toner supply section for supplying the toner from the
toner cartridge to the developer container; a toner remaining
amount detecting section for detecting individual remaining amounts
of the toners contained in the toner cartridges; and a control
section for controlling the toner supply section to select the
toner cartridge having the least toner remaining amount detected by
the toner remaining amount detecting section, and to supply the
toner from the selected toner cartridge to the developer
container.
2. The image forming apparatus of claim 1, wherein the toner
remaining amount detecting section is disposed in each of the toner
cartridges, and the toner remaining amount detecting section
includes a nonvolatile memory in which toner remaining amount
detection information which is information on the remaining amount
of the toner contained in the toner cartridge, is stored.
3. The image forming apparatus of claim 2, wherein the toner
remaining amount detecting section includes a first wireless
transmitting/receiving section for transmitting the toner remaining
amount detection information stored in the nonvolatile memory, to
an outside, and the control section includes a second wireless
transmitting/receiving section for receiving the toner remaining
amount detection information transmitted from the first wireless
transmitting/receiving section, thereby to control the toner supply
section in accordance with the toner remaining amount detection
information obtained by the second wireless transmitting/receiving
section.
4. The image forming apparatus of claim 1, wherein the toner supply
section is a rotational drive section which is disposed in each of
the toner cartridges, for rotating the toner cartridge to supply
the toner.
5. The image forming apparatus of claim 4, wherein the toner
cartridge includes a rotation number detecting unit for detecting a
number of rotations of the toner cartridge, wherein the accumulated
value of the number of rotations of the toner cartridge which
number of rotations is detected by the rotation number detecting
unit, is stored as the toner remaining amount detection information
in the nonvolatile memory.
6. The image forming apparatus of claim 4, wherein the toner
cartridge includes a rotation number detecting unit for detecting a
number of rotations of the toner cartridge, and a remaining amount
calculating section for calculating the remaining amount of the
toner reserved in the toner cartridge, from the accumulated value
of the number of rotations of the toner cartridge which number of
rotations is detected by the rotation number detecting unit,
wherein the toner remaining amount calculated by the remaining
amount calculating section is stored as the toner remaining amount
detection information in the nonvolatile memory.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an image forming
apparatus.
[0003] 2. Description of the Related Art
[0004] An image forming apparatus using the electronic photography
is generally constituted to include a photoreceptor which is a
rotating image bearing member, and a charging section, an exposure
section, a developing section, a transfer section, a fixing
section, a cleaning section and a deelectrification section, which
are arranged around the photoreceptor. The charging section charges
the surface of the photoreceptor uniformly. The exposure section
exposes the photoreceptor surface charged, to light according to
image information thereby to form an electrostatic latent image.
The developing section agitates and charges the toner so that a
toner image is formed by adhering the frictionally charged toner to
the electrostatic latent image formed on the photoreceptor surface.
The transfer section transfers the toner image to a recording
medium by charging the recording medium into the polarity reversed
from that of the toner. The fixing section fixes the transferred
toner image on the recording medium by, for example, heating and
pressurizing. The cleaning section recovers the toner which is not
transferred to the recording medium but left on the photoreceptor
surface. The deelectrification section carries out
deelectrification of the photoreceptor in a state where the toner
image has been transferred therefrom. By the image forming
apparatus using the electrostatic photography thus constituted, a
desired image is formed on the recording medium.
[0005] This image forming apparatus is equipped with a toner supply
section for supplying the toner to a developer container which is a
container belonging to the developing section for containing the
toner, because the toner used for the development in the developing
section is consumed. The toner supply section supplies the
developer container with the toner in the toner cartridge which is
usually constituted so as to be attachable to and removable from
the image forming apparatus. When the toner in the toner cartridge
is exhausted as a result of the supply to the developer container,
the image forming apparatus interrupts its actions. By replacing
the toner cartridge having its toner exhausted by a new toner
cartridge, however, the image forming apparatus is supplied with
the toner so that it can perform again the image forming
actions.
[0006] In recent years, there has been developed an image forming
apparatus such as a copier or printer of electronic photography,
which is intended for heavy users to consume much toner. In this
apparatus, as much as toner is contained in one toner cartridge
thereby to reduce the number of exchanges of the toner cartridge.
When this large-sized toner cartridge containing much toner is
used, the number of exchanges can be reduced to interrupt the image
forming actions less frequently. It is, therefore, desired to
lighten the burden on the user unfamiliar to the handling of the
apparatus.
[0007] When much toner is contained in one toner cartridge, the
number of interruptions of the image forming actions can be reduced
by reducing the number of replacements of the toner cartridge. At
the time of replacing the toner cartridges, however, it is
impossible to avoid the interruption of the image forming actions.
As a technique for solving this problem, there has been proposed an
image forming apparatus (in Japanese Unexamined Patent Publications
JP-A 8-137227 (1996) and JP-A 2003-208007, for example), which is
equipped with a plurality of toner cartridges for containing toner
of an identical color and which uses the (continuous run) system
for automatically replacing the toner cartridge to be supplied with
the toner.
[0008] The image forming apparatus, as disclosed in JP-A 8-137227,
is equipped with a plurality of toner cartridges for storing the
toner of an identical color, and toner transfer conduits connected
to the plural toner cartridges and merging midway to transfer the
toner discharged from the toner cartridge to the inside of the
developer container. In the image forming apparatus disclosed in
JP-A 8-137227, the toner is supplied from one of the plural toner
cartridges. The toner can be supplied, when exhausted in one toner
cartridge, from another toner cartridge so that its supply does not
interrupt the image forming actions.
[0009] In the image forming apparatus disclosed in JP-A
2003-208007, on the other hand, the color image forming apparatus
is equipped with a plurality of toner cartridges for a black color
to be more consumed than the color toners of yellow, magenta and
cyan, and the black toner cartridges are arranged in one row
adjacent to each other. According to this image forming apparatus
disclosed in JP-A2003-208007, the plural black toner cartridges can
prevent the interruptions of the image forming actions from being
frequently caused by the exhaustion of the black toner. Since the
plural black toner cartridges are arranged in one row adjacent to
each other, it is possible to spare the space for the toner
containing portion and not to mistake the positions for mounting
the toner cartridges.
[0010] Here in this image forming apparatus, after the toner
cartridge mounted on one toner cartridge mounting portion was used
to the last, this mounting portion may be loaded with the toner
cartridge before the end of use, which has been employed in another
image forming apparatus, or the toner cartridge which has been
stored in the unconsumed state. The toner cartridge before the end
of use is desirably employed as early as possible, because the
toner contained therein is degraded in the charging characteristics
and fluidity by the environmental influences such as humidity after
left unused for a long time.
[0011] In the image forming apparatus disclosed in JP-A8-137227 and
in JP-A 2003-208007, the toner cartridges mounted on the two toner
cartridge mounting portions are constituted such that they are
alternately employed for their individual mounting portions. In
case the two mounting portions are provided, which are individually
equipped with the toner cartridges, when the toner cartridge of one
mounting portion is used up, the toner cartridge of the other
mounting portion is employed. While the toner cartridge of the
other mounting portion is being employed, the toner cartridge of
one mounting portion is replaced by new one. In case this replaced
toner cartridge is before the end, this toner cartridge before the
end is not employed till the toner of the toner cartridge mounted
on the other mounting portion is exhausted.
[0012] In the image forming apparatus disclosed in JP-A 8-137227
and JP-A 2003-208007 thus constituted, the toner cartridges mounted
in the individual mounting portions are alternately employed for
the individual mounting portions, but no consideration is taken
into the used situations of the toner. In order to employ the toner
cartridge before the end to be earlier employed, therefore, the
complicated procedure is required for exchanging the unused toner
cartridge to be mounted on the other mounting portion and the toner
cartridge before the end of use. During this replacing procedure,
moreover, there occurs a time period, for which none of the toner
cartridges is mounted, to raise a problem that the image forming
actions are interrupted.
SUMMARY OF THE INVENTION
[0013] An object of the invention is to provide an image forming
apparatus capable of using such a toner cartridge preferentially
without interrupting an image forming action as is desired for an
early use and as has a less toner remaining amount.
[0014] The invention provides an image forming apparatus
comprising:
[0015] a developing section for developing with toner contained in
a developer container;
[0016] a plurality of toner cartridges for containing toners of an
identical color;
[0017] a toner supply section for supplying the toner from the
toner-cartridge to the developer container;
[0018] a toner remaining amount detecting section for detecting
individual remaining amounts of the toners contained in the toner
cartridges; and
[0019] a control section for controlling the toner supply section
to select the toner cartridge having the least toner remaining
amount detected by the toner remaining amount detecting section,
and to supply the toner from the selected toner cartridge to the
developer container.
[0020] According to the invention, there is provided an image
forming apparatus comprising: a plurality of toner cartridges for
containing toners of an identical color; a toner supply section for
supplying the toner from the toner cartridge to the developer
container; a toner remaining amount detecting section for detecting
individual remaining amounts of the toners contained in the toner
cartridges; and a control section for controlling the toner supply
section to select the toner cartridge having the least toner
remaining amount detected by the toner remaining amount detecting
section, and to supply the toner from the selected toner cartridge
to the developer container. In this image forming apparatus, the
toner can be preferentially supplied from the toner cartridge of
the least toner remaining amount to the developer container.
Therefore, when the toner cartridge before the end of use is
employed, the toner cartridge before the end of use and to be
earlier used can be preferentially employed. This makes it possible
to prevent the toner cartridge before the end of use from being
degraded in the charging characteristics and fluidity of the toner,
as might otherwise be caused after left unused for a long time, so
that an image of high quality can always be formed.
[0021] In the invention, it is preferable that the toner remaining
amount detecting section is disposed in each of the toner
cartridges, and the toner remaining amount detecting section
includes a nonvolatile memory in which toner remaining amount
detection information which is information on the remaining amount
of the toner contained in the toner cartridge, is stored.
[0022] According to the invention, moreover, the toner remaining
amount detecting section is disposed in each of the toner
cartridges, and the toner remaining amount detecting section
includes the nonvolatile memory in which the toner remaining amount
detection information which is the information on the remaining
amount of the toner contained in the toner cartridge, is stored. As
a result, it is possible to easily grasp the toner remaining amount
in the toner cartridge.
[0023] Furthermore, in the invention, it is preferable that the
toner remaining amount detecting section includes a first wireless
transmitting/receiving section for transmitting the toner remaining
amount detection information stored in the nonvolatile memory, to
an outside, and the control section includes a second wireless
transmitting/receiving section for receiving the toner remaining
amount detection information transmitted from the first wireless
transmitting/receiving section, thereby to control the toner supply
section in accordance with the toner remaining amount detection
information obtained by the second wireless transmitting/receiving
section.
[0024] According to the invention, moreover, the toner remaining
amount detecting section includes the first wireless
transmitting/receiving section disposed in each of the toner
cartridges for transmitting the toner remaining amount detection
information stored in the nonvolatile memory, to the outside, and
the control section includes the second wireless
transmitting/receiving section for receiving the toner remaining
amount detection information transmitted from the first wireless
transmitting/receiving section, thereby to control the toner supply
section in accordance with the toner remaining amount detection
information obtained by the second wireless transmitting/receiving
section. As a result, the toner remaining amount detecting section
and the control section can communicate in a non-contact manner so
that the arrangement of the toner remaining amount detecting
section and the control section can be freely set to spare the
space for the apparatus.
[0025] Furthermore, in the invention, it is preferable that the
toner supply section is a rotational drive section which is
disposed in each of the toner cartridges, for rotating the toner
cartridge to supply the toner.
[0026] According to the invention, moreover, the toner supply
section is a rotational drive section which is disposed in each of
the toner cartridges, for rotating the toner cartridge to supply
the toner. The supply of the toner by the rotation of the toner
cartridge is performed, for example, by rotating the toner
cartridge of a substantially cylindrical shape about an axis
thereof so that the toner may be guided to and fed out from an
opening formed in the toner cartridge. This toner supply can make
constant the quantity of toner to be fed by the rotation to the
opening so that the supply amount of the toner can be stabilized to
a predetermined value. Moreover, the toner can be prevented from
sticking to the inner wall of the toner cartridge by the rotation
of the toner cartridge and accordingly from being left in the toner
cartridge. Moreover, it is unnecessary to provide the toner
cartridge with a complicated agitating section for preventing the
toner from agglomerating in the toner cartridge.
[0027] Furthermore, in the invention, it is preferable that the
toner cartridge includes a rotation number detecting unit for
detecting a number of rotations of the toner cartridge,
[0028] wherein the accumulated value of the number of rotations of
the toner cartridge which number of rotations is detected by the
rotation number detecting unit, is stored as the toner remaining
amount detection information in the nonvolatile memory.
[0029] According to the invention, moreover, the toner cartridge
includes the rotation number detecting unit for detecting the
number of rotations of the toner cartridge, wherein the accumulated
value of the number of rotations of the toner cartridge which
number of rotations is detected by the rotation number detecting
unit, is stored as the toner remaining amount detection information
in the nonvolatile memory. As a result, the weight of the toner
contained in the toner cartridge can be easily detected without
providing a weight sensor for detecting the toner weight in the
toner cartridge.
[0030] Furthermore, in the invention, it is preferable that the
toner cartridge includes a rotation number detecting unit for
detecting a number of rotations of the toner cartridge, and a
remaining amount calculating section for calculating the remaining
amount of the toner reserved in the toner cartridge, from the
accumulated value of the number of rotations of the toner cartridge
which number of rotations is detected by the rotation number
detecting unit,
[0031] wherein the toner remaining amount calculated by the
remaining amount calculating section is stored as the toner
remaining amount detection information in the nonvolatile
memory.
[0032] According to the invention, moreover, the toner cartridge
includes the rotation number detecting unit for detecting the
number of rotations of the toner cartridge, and the remaining
amount calculating section for calculating the remaining amount of
the toner reserved in the toner cartridge, from the accumulated
value of the number of rotations of the toner cartridge which
number of rotations is detected by the rotation number detecting
unit, wherein the toner remaining amount calculated by the
remaining amount calculating section is stored as the toner
remaining amount detection information in the nonvolatile memory.
As a result, the weight of the toner in the toner cartridge can be
easily detected without any weight sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Other and further objects, features, and advantages of the
invention will be more explicit from the following detailed
description taken with reference to the drawings wherein:
[0034] FIG. 1 is a diagram showing a constitution of an image
forming apparatus according to one embodiment of the invention;
[0035] FIG. 2 is an enlarged diagram schematically showing a
constitution around a developing section, as belonging to the image
forming apparatus shown in FIG. 1, of a black image;
[0036] FIGS. 3A and 3B are diagrams showing a constitution of a
toner cartridge in a simplified form;
[0037] FIG. 4 is a perspective view showing a central container
portion belonging to the toner cartridge shown in FIG. 3A and FIG.
3B;
[0038] FIGS. 5A to 5D are sectional views showing an outline of an
action to supply toner to the developing section of the toner
cartridge; and
[0039] FIG. 6 is a block diagram showing an electric configuration
relating to the actions, as based on information stored in a
wireless IC tag, of a control section.
DETAILED DESCRIPTION
[0040] Now referring to the drawings, preferred embodiments of the
invention are described below.
[0041] FIG. 1 is a diagram showing a constitution of an image
forming apparatus 1 according to one embodiment of the invention,
and FIG. 2 is an enlarged diagram schematically showing a
constitution around a developing section 14K, as belonging to the
image forming apparatus 1 shown in FIG. 1, of a black image.
[0042] The image forming apparatus 1 is a full-color image forming
apparatus using the electronic photography, as exemplified a
multifunctional system having the functions of a copier, a printer
and the like.
[0043] The image forming apparatus 1 is constituted to include an
image information reading unit 2, an image processing unit (not
shown), an image forming unit 3, a paper feeding unit 4, a fixing
unit 5, a paper discharge unit 6 and a control section 7. The image
information reading unit 2 reads image information of a document.
The image processing unit image processes either the image
information read by the image information reading unit 2 or image
information inputted from an external device such as a personal
computer. The image forming unit 3 forms an image on the basis of
image information outputted from the image processing unit. The
paper feeding unit 4 feeds the sheet of recording paper to the
image forming unit 3. The fixing unit 5 fixes the image which has
been formed in the image forming unit 3 and transferred to the
sheet of recording paper. The paper discharge unit 6, to which the
sheet of recording paper having the fixed image is discharged. The
control section 7 controls the actions of the whole image forming
apparatus 1.
[0044] The image forming apparatus 1 is characterized in that, when
the toner of an identical color (e.g., black in this embodiment) is
to be supplied to a developer container 15K from a plurality of
(e.g., two in this embodiment) toner cartridges 8K1 and 8K2
containing that toner, the control section 7 controls the actions
of motors 9K1 and 9K2 as a toner supply section for supplying the
toner from the toner cartridges 8K1 and 8K2 to the developer
container 15K, to select a toner cartridge 8 having the least toner
content detected by the later-described wireless IC tag as the
toner remaining amount detecting section for detecting the
remaining amounts of toners contained in the toner cartridges 8K1
and 8K2, individually, and to supply the toner from the toner
cartridge 8 to the developer container 15K.
[0045] The image information reading unit 2 reads out the image
information of the document placed on a document platen 10. The
image information reading unit 2 is constituted to include the
not-shown document scanning unit adapted to be reciprocally moved
in parallel with the lower face of the document platen 10, an
optical lens, and a CCD (charge coupled device) line sensor which
is a photoelectric conversion element. The image information
reading unit 2 reads out a monochrome image or color image of the
document placed on the document platen 10, and outputs the image
information of that image to the image processing unit (not shown)
. This image processing unit converts the image information, as
inputted from the external device such as the image information
reading unit 2 or the personal computer, into electric signals of
individual colors, and outputs the electric signals individually to
an exposure unit 13 of the image forming unit 3.
[0046] The image forming unit 3 is constituted to include a
photoreceptor 11 for having an electrostatic latent image formed on
its surface, a charger 12, the exposure unit 13, a developing
section 14, a transfer unit 16 and a cleaning section 17. The
charger 12, the exposure unit 13, the developing section 14, the
transfer unit 16 and a cleaning section 17 are disposed around the
photoreceptor 11. The charger 12 charges the photoreceptor 11
uniformly. The exposure unit 13 exposes the surface of the charged
photoreceptor 11 to light according to the image information
outputted from the image processing unit, and forms the
electrostatic latent image. The developing section 14 forms a toner
image on the surface of the photoreceptor 11 with the toner
contained in a developer container 15. The transfer unit 16
transfers the toner image formed on the surface of the
photoreceptor 11 by the developing section 14 to the sheet of
recording paper. The cleaning section 17 cleans the surface of the
photoreceptor 11 after the toner image has been transferred by the
transfer unit 16.
[0047] Here, the image forming unit 3 is formed integrally with the
exposure unit 13 but is equipped with the individual units for
forming a black image, a cyan image, a magenta image and a yellow
image. In FIG. 1, therefore, the image forming unit 3 is indicated
by attaching alphabets K (black), C (cyan), M (magenta) and Y
(yellow) to the tail thereof. In FIG. 2, on the other hand, the
individual units of the image forming unit 3K for forming the black
image are expressed by attaching the alphabet K indicating the
black to the tails of the aforementioned reference numerals.
[0048] As to the image forming unit 3, the image forming unit 3K
for the black image is described as a representative with reference
to FIG. 2. The image forming units 3 for the remaining colors are
constituted identically to the image forming unit 3K for the black
color except that one toner cartridge is provided and that the
individual units of the toner cartridge 8 and the image forming
unit 3 have different sizes, so that their descriptions are
omitted.
[0049] Here, the individual units of the black image forming unit
3K are made larger than the individual units of the remaining color
image forming units 3. This is because it is anticipated that the
number of times for forming the black color is larger than those
for forming the images of the other colors. In case the black image
forming unit 3K is formed to have the same size as those of the
other color image forming units 3, the number of forming the black
image becomes larger than the number of forming the image of the
other colors, thereby the number of rotations of the photoreceptor
11K becomes larger than those for the other colors so that the
lifetime of the photoreceptor 11K becomes shorter than those of the
photoreceptors 11 for the other colors.
[0050] Therefore, the photoreceptor 11K is made larger than the
other color photoreceptors 11 so that no substantial difference may
not arise from the lifetimes of the other color photoreceptors 11.
The developing section 14K for the black image forming unit 3K is
made so larger than the other color developing section 14K as to
match the size of the black image forming photoreceptor 11 larger
than the other color photoreceptors 11. Here, the image forming
apparatus 1 of the invention should not be limited to the
constitution, in which the individual units of the black image
forming unit 3 are larger than those of the other color image
forming units 3, but may also be constituted such that all the
individual units of the black, cyan, magenta and yellow image
forming units 3 are made to have an equal size.
[0051] The exposure unit 13 is constituted of an optical unit (LSU:
Laser Scanning Unit) including a semiconductor laser element for
emitting a laser beam which is a dot beam which is modulated
according to pixel signals inputted from the image processing unit,
and a mirror for guiding the beam emitted from the semiconductor
laser element, into the photoreceptors 11 for the individual
colors.
[0052] The developing section 14K develops the electrostatic latent
image formed by the exposure unit 13 on the surface of the
photoreceptor 11, thereby to visualize the latent image by forming
a toner image. The developing section 14K includes a developing
roller 18K, an agitating roller 19K, a developer container 15K, a
toner hopper 20K, a toner supply roller 21K, a toner feeding roller
22K, the toner cartridges 8K1 and 8K2. The developing roller 18K is
disposed to face the photoreceptor 11K and feeds the toner to the
electrostatic latent image on the surface of the photoreceptor 11K.
The agitating roller 19K agitates and transports the developer to
the developing roller 18K. The developer container 15K houses the
developing roller 18K and the agitating roller 19K. The developing
roller 18K and the agitating roller 19K are rotatably mounted in
the developer container 15K. The toner hopper 20K is a container
formed to communicate with the developer container 15K through a
hopper supply port (not shown) and for supplying the developer
container 15K with the toner. The toner supply roller 21K is
disposed just above the hopper supply port for feeding the toner
from the toner hopper 20K to the developer container 15K. The toner
feeding roller 22K feeds the toner to the toner supply roller 21K.
The toner cartridges 8K1 and 8K2 supply the developer toner to the
developer container 15K through the toner hopper 20K.
[0053] The developer container 15K is a container made of a hard
synthetic resin, for example, for containing the toner, and is
formed integrally with the toner hopper 20K. In or near the
developer container 15K, a toner density sensor (not shown) is
disposed for detecting the toner density in the developer container
15K. The detection result of the toner density by the toner density
sensor is outputted to the control section 7.
[0054] The toner to be supplied to the developer container 15K is
contained in the toner cartridge 8 which is removably mounted in
the image forming apparatus 1. This image forming apparatus 1 of
this embodiment is equipped, as its toner cartridge 8, with two
black toner cartridges (as will be conveniently called the first
toner cartridge 8K1 and the second toner cartridge 8K2), and each
one of the cyan color toner cartridge 8C, the magenta color toner
cartridge 8M and the yellow toner cartridge 8Y. Each toner
cartridge 8 has a substantially cylindrical shape and is connected
with a motor 9 acting as a rotational drive section for rotating
the toner cartridge 8 about its rotation axis. The motor 9 rotates
the toner cartridge 8 thereby to supply the toner.
[0055] Here, the individual toner cartridges for the black, cyan,
magenta and yellow colors are formed to have substantially
identical shapes. Since it is expected that the consumption rate of
the black toner is more than those of the other colors, the black
toner cartridges 8K1 and 8K2 are made diametrically larger than
those of the individual cartridges for the cyan, magenta and yellow
colors. However, all the cartridges may also have identical
sizes.
[0056] Moreover, the image forming apparatus 1 of this embodiment
is exemplified by an intermediate speed machine (having an image
forming ability of about 30 sheets per minute), and the number of
the black toner cartridges 8K1 and 8K2 is two. It is, however,
preferable that the number of black toner cartridges is increased,
for example, three, as the image forming ability becomes high.
[0057] FIGS. 3A and 3B are diagrams showing the constitution of the
toner cartridge 8 in a simplified form, and FIG. 4 is a perspective
view showing a central container portion 23 belonging to the toner
cartridge 8 shown in FIGS. 3A and 3B. The toner cartridge 8 is
formed of a hard synthetic resin, for example, into such a bottomed
generally cylindrical shape that the corner portion in a cross
section normal to the rotation axis 28 is curved to have no corner.
The outer diameter of the toner cartridge is exemplified such that
the black toner cartridge has a diameter D of 110 mm, a length L of
450 mm and a toner containing capacity of about 4,000 cm.sup.3. The
toner cartridges for the individual cyan, magenta and yellow colors
have a diameter D of 78 mm, a length L of 450 mm and a toner
containing capacity of about 2,000 cm.sup.3.
[0058] The toner cartridge 8 is substantially constituted to
include: the central container portion 23 disposed substantially at
the central portion in a longitudinal direction; first and second
container portions 24 and 25 disposed to extend from the central
container portion 23 toward opposite sides of the longitudinal
direction; and a support member 26 disposed to cover an outer
circumference of the central container portion 23. Moreover, each
toner cartridge 8 is equipped, at its central container portion 23,
with a wireless IC tag 27 acting as a toner remaining amount
detecting section for detecting the remaining amount of the toner
contained in the toner cartridge 8. This toner cartridge 8 is
rotationally driven about the rotation axis 28 in the direction of
an arrow 29 by the motor 9 acting as the rotational drive
section.
[0059] The first and second container portions 24 and 25 of the
toner cartridge 8 are containers of a bottomed cylindrical shape
both having an opening on one end, and are so individually mounted
on the central container portion 23 that the internal spaces of the
first and second container portions 24 and 25 and the internal
space of the central container portion 23 may communicate through
the openings. The central container portion 23 is formed into a
substantially cylindrical shape, and has a recess 30 having a slope
in the substantially central portion in the longitudinal direction
over about one quarter of the outer circumference thereof.
[0060] The recess 30 is formed to include a step portion 31
recessed in a radial direction of the central container portion 23,
and a slope portion 32 formed to become shallower from the
downstream side to the upstream side in the rotational direction 29
of the toner cartridge 8. In a falling portion 31a inward of the
radial direction of the step portion 31, there is formed an opening
33, which communicates with the internal space of the central
container portion 23. According to the rotating action of the toner
cartridge 8 in the direction of the arrow 29, the toner contained
in the toner cartridge 8 is discharged from that opening 33, which
will be called the toner discharge port 33.
[0061] The support member 26 disposed to cover the central
container portion 23 is a member for rotatably supporting the
central container portion 23 and the first and second container
portions 24 and 25 of the toner cartridge 8 rotated by the motor 9.
The support member 26 is equipped, at its position corresponding in
the longitudinal direction to the recess 30 formed in the central
container portion 23, with a leading through hole 34 leading to the
outer circumference of the central container portion 23, and a
shutter member 35 for opening/closing the leading through hole 34
temporarily. The shutter member 35 is constituted to include a
guide member 35a, a cover member 35b and a drive mechanism (not
shown). The guide member 35a is disposed in the longitudinal
direction of the toner cartridge 8. The cover member 35b makes
slidable in the longitudinal direction of the toner cartridge 8
while being guided by the guide member 35a, thereby to open/close
the leading through hole 34. The not-shown drive mechanism slides
the cover member 35b.
[0062] The leading through hole 34 of the support member 26 is
constituted to communicate with the developer container 15 of the
developing section 14 through a leading member 36 and the toner
hopper 20. As a result, when the container portion of the toner
cartridge 8 rotates in the direction of the arrow 29, the toner
contained in the toner cartridge 8 is discharged in a predetermined
quantity from the toner discharge port 33, and the toner discharged
is transferred by the slope portion 32 to the outer circumference
of the central container portion 23 so that the toner transferred
is supplied to the developer container 15 through the leading
through hole 34 in the open state and through the leading member
36. FIG. 1 shows only the leading member 36 for feeding the toner
contained in the black toner cartridges 8K1 and 8K2, but omits the
leading members for feeding the cyan, magenta and yellow
toners.
[0063] The leading member 36 is constituted to include a toner
receiving portion 37 formed in a funnel shape, and a conduit
portion 38. The toner discharged in the predetermined quantity from
the toner discharge port 33 through the leading through hole 34 is
discharged to the toner receiving portion 37 and fed to the conduit
portion 38 so that the toner is supplied to the developer container
15 through the toner hopper 20 from the conduit portion 38.
[0064] FIGS. 5A to 5D are sectional views showing an outline of the
action to supply the toner to the developing section 14 of the
toner cartridge 8. The actions of the toner cartridge at the time
when the toner of the predetermined quantity is fed from the toner
cartridge 8 to the developer container 15 will be further described
with reference to FIGS. 5A to 5D.
[0065] In FIG. 5A, the rotational position of the toner cartridge 8
is located such that the recess 30 and the toner discharge port 33
formed in the central container portion 23 are positioned above the
upper face 39a (as will be called the toner layer face 39a) of the
toner 39 contained in the central container portion 23. When the
central container portion 23 of the toner cartridge 8 rotates about
the rotation axis 28 in the direction of the arrow 29 so that the
toner discharge port 33 comes to a position below the toner layer
face 39a, the toner 39 in the central container portion 23 flows
into the recess 30 through the toner discharge port 33, as
indicated by arrow 39c.
[0066] When the toner cartridge 8 further rotates in the direction
of the arrow 29, the toner discharge port 33 is positioned above
the toner layer face 39a, as shown in FIG. 5C, the flow the toner
39 into the recess 30 through the toner discharge port 33 is
stopped, so that the toner 39b of a predetermined quantity is held
in a space 40 which is defined by the recess 30 of the central
container portion 23 and by the inner wall of the support member
26. The quantity of the toner 39b, which is thus held in the space
40 formed by the recess 30 and the inner wall of the support member
26, is 6 grams, for example.
[0067] When the toner cartridge 8 further rotates in the direction
of the arrow 29 from the state shown in FIG. 5C, the toner 29b,
which is held in the space 40 formed by the recess 30 and the inner
wall of the support member 26, is guided into the toner discharge
port 33 while being guided by a guide member 41 which can slide in
elastic abutment against the outer circumference of the central
container portion 23. At this time, the guide member 41 slides in
abutment against the outer circumference of the central container
portion 23 so that the guide member 41 can guide the toner 39 held
in the recess 30, as wholly as possible into the toner discharge
port 33. The toner 39b thus guided into the toner discharge port 33
is fed via the leading member 36 and through the toner hopper 20
into the developer container 15 of the developing section 14. Thus,
the toner 39 contained in the toner cartridge 8 is fed in the
predetermined quantity to the developer container 15 as the toner
cartridge 8 makes one rotation.
[0068] In the central container portion 23, there is also formed
another recess 42, which is located at a position substantially
symmetric to the aforementioned recess 30 with respect to the
rotation axis 28. As a result, another space 43 is formed between
the other recess 42 and the inner wall of the support member 26.
This other space 43 is provided for holding the developer, in case
the toner 39b held in the space 40 leaks from a side of the space
40 upstream in the rotation direction indicated by the arrow 29.
Like the toner 39b held in the space 40, the developer held in that
other space 43 is guided, as the central container portion 23
rotates in the direction of the arrow 29, into the toner discharge
port 33 by the guide member 41 which slides in abutment against the
outer circumference of the central container portion 23. Thus, the
toner 39b, if having leaked from the space 40, is held by the other
space 43 and is guided by the guide member 41 into the toner
discharge port 33 so that the toner of the predetermined quantity
can be reliably fed to the developing section 14.
[0069] When the toner cartridge 8 is formed such that the corner
portion in the section normal to the rotation axis 28 is curved to
have no corner, as described herein before, its internal space is
also formed to have no corner. As a result, the discharge of the
toner accompanying the rotation is smoothed to leave little toner
in the internal space, but the toner remaining amount is used up to
the lower limit so that the toner cartridge removed from the
apparatus body can be easily cleaned in its inside and eliminated
for easy reuse in a substantially complete state without any toner
being left.
[0070] On one end portion of the toner cartridge 8, i.e., at the
bottom portion of the second container portion 25, moreover, there
is mounted a rotation number detecting unit 44 for counting the
number of rotations of the container portion of the toner cartridge
8. The rotation number detecting unit 44 used is equipped with a
known rotating meter of the type for outputting a signal for one
rotation, and a transmission unit for transmitting a signal output
to the wireless IC tag 27 which is the toner remaining amount
detecting section for detecting the remaining amount of the toner
contained in the toner cartridge 8. This rotation number detecting
unit 44 will be simply called the rotating meter 44.
[0071] The wireless IC tag 27 is disposed in each of the toner
cartridges 8. The wireless IC tag 27 is constituted to include: an
IC chip unit 45 which is a nonvolatile memory for storing the toner
remaining amount detection information on the remaining amount of
the toner contained in the toner cartridge 8; an antenna unit 46 as
a first wireless transmitting/receiving section for transmitting
the toner remaining amount detection information stored in the IC
chip unit 45, to the outside; and a base film 47 having the IC chip
unit 45 and the antenna unit 46 mounted thereon. The wireless IC
tag 27 as the toner remaining amount detecting section is disposed
in the central container portion 23.
[0072] The base film 47 is a film made of polyester, for example.
The base film 47 is mounted such that its one end portion slightly
protrudes from the slope portion 32 onto the outer circumference of
the central container portion 23. This base film protrusion 47a
from the slope portion 32 functions as a scraper for feeding the
toner, as discharged from the toner discharge port 33 and
transferred along the slope portion 32 to the vicinity of the outer
circumference of the central container portion 23, smoothly into
the leading through hole 34.
[0073] The antenna unit 46 is a communication unit for transferring
and receiving the information with the rotating meter 44 and for
transmitting the toner remaining amount detection information to be
stored in the IC chip unit 45, to a later-described communication
device which is a second wireless transmitting/receiving section
contained in the control section 7.
[0074] The IC chip unit 45 is a storage unit forming a major
portion of the wireless IC tag 27. This IC chip unit 45 can store
identification information for identifying the kind of the toner
cartridge 8, and the toner remaining amount detection information
on the remaining amount of the toner by the rotating meter 44.
Here, the identification information for identifying the kind of
the toner cartridge 8 indicates what of the black toner, the cyan
toner, the magenta toner and the yellow toner the toner contained
in the toner cartridge 8 is. This identification information is
inputted to the IC chip unit 45 by the dedicated input device when
the toner cartridge is manufactured and charged with the toner of
each color.
[0075] The toner remaining amount detection information is stored
as an accumulated value of the number of rotations detected by the
rotating meter 44. The toner of the predetermined quantity is
discharged for each rotation of the container portion of the toner
cartridge 8, as described herein before, so that the information on
the total of the toner discharged can be acquired in terms of the
accumulated value of the number of rotations. The detection
information of the number of rotations by the rotating meter 44 is
rewritten and inputted in real time, as the image forming apparatus
1 moves, into the IC chip unit 45 through the antenna unit 46 of
the wireless IC tag 27. Here, the wireless IC tag 27 may store, in
addition to the aforementioned information, other pieces of
information such as the sheet number of the image-formed sheet of
recording paper, the process condition or the developing
condition.
[0076] The control section 7 controls the actions of the motor 9 as
the toner supply section for supplying the toner from the toner
cartridge 8 to the developer container 15, i.e., the rotational
drive section for supplying the toner, when it rotates the toner
cartridge 8. The control section 7 rotates the motor 9 to supply
the toner from the toner cartridge 8, when the toner density, as
outputted from the toner density sensor disposed in or near the
developer container 15, in the developer container 15 becomes lower
than a predetermined density. Here, this predetermined density is
properly determined to a value higher than the lower limit of the
toner density for a satisfactory image density.
[0077] When the toner density in the black image developer
container 15K, as supplied with the toner from one of the two toner
cartridges 8K1 and 8K2, becomes lower than the predetermined
density, the control section 7 controls the actions of the motor
9K1 or 9K2 as the toner supply section to select the toner
cartridge 8, the remaining amount of which is detected at the least
by the wireless IC tag 27 which is the toner remaining amount
detection section, and to supply the toner from that toner
cartridge 8 to the developer container 15K. The control section 7
acquires the remaining amount of the toner in each toner cartridge
8 by the following electric configuration.
[0078] FIG. 6 is a block diagram showing an electric configuration
relating to the actions, as based on the information stored in the
wireless IC tag 27, of the control section 7. This control section
7 is equipped with a communication device 48 as the second wireless
transmitting/receiving section for receiving the toner remaining
amount detection information transmitted from the wireless IC tag
27.
[0079] The detected output of the number of rotations of the
rotating meter 44 is fed, as has been described herein before, from
the communication unit of the rotating meter 44 through the antenna
unit 46 of the wireless IC tag 27 to the IC chip unit 45 so that it
is stored as the accumulated value of the number of rotations.
[0080] When it is detected by the toner density detecting sensor
that the toner density in the developer container 15 of a color is
lower than a predetermined toner value, the communication device 48
transmits such a signal to the antenna unit 46 of the wireless IC
tag 27 belonging to the toner cartridge 8 for the corresponding
color as to request that the toner remaining amount detection
information on the toner remaining amount is transmitted to the
communication device 48. In response to this signal, the antenna
unit 46 of the wireless IC tag 27 belonging to the toner cartridge
8 for the corresponding color transmits the accumulated value, as
read out as the toner remaining amount detection information on the
remaining amount of the toner, of the number of rotations to the
communication device 48 of the communication section 7.
[0081] The control section 7 is equipped with a storage unit (not
shown), which is prestored with both the initial value of the
quantity of the toner to be contained at the time of manufacturing
the toner cartridge 8 and the quantity of toner to be discharged
for one rotation of the toner cartridge 8. With the value prestored
in the storage unit and with the accumulated value of the number of
rotations received by the communication device 48, the calculation
expressed by Equation (1) is executed to acquire the remaining
amount of the toner to be contained in the toner cartridge 8: Toner
Remaining Amount=(Initial Toner Quantity-Toner discharge for One
Rotation.times.Accumulated Number of Rotations) (1).
[0082] In the control section 7, when the toner remaining amount
obtained by Equation (1) is the lower limit predetermined and
stored in the storage unit or less (i.e., empty less than the lower
limit of the available quantity), it is indicated, for example, in
a display unit 49 of the image forming apparatus 1 that the toner
cartridge for that color is at the timing for replacement. In view
of these display contents, the operator of the image forming
apparatus 1 executes the replacement of the toner cartridge.
[0083] The control section 7 thus acquiring the toner remaining
amount detection information controls the motors 9K1 and 9K2 in the
following manners, when the toner density in the developer
container 15K for the black image becomes lower than the
predetermined value. At first, the control section 7 causes the
communication device 48 to transmit the signal requesting the
transmission of the toner remaining amount detection information,
to the antenna units 46K1 and 46K2 of the wireless IC tags 27K1 and
27K2 belonging to the first black toner cartridges 8K1 and 8K2,
respectively. In response to this signal, the antenna units 46K1
and 46K2 transmit the individual pieces of toner remaining amount
detection information of the individual toner cartridges 8 to the
communication device 48.
[0084] In response to the toner remaining amount detection
information transmitted to the communication device 48, the control
section 7 drives either the motor 9K1 or the motor 9K2 to supply
the toner from the toner cartridge 8 having the less toner
remaining amount, so that the toner may be supplied from the toner
cartridge 8 having the less toner remaining amount. Thus, the toner
cartridge 8 detected to have the least toner remaining amount by
the wireless IC tag 27 is selected, and the motor 9 is controlled
to supply the toner from the toner cartridge 8 to the developer
container 15K.
[0085] Reverting to FIG. 1, the transfer unit 16 is described. This
transfer unit 16 is constituted to include a drive roller 50, a
driven roller 51, an intermediate transfer belt 52 of an endless
shape, four intermediate transfer rollers 53 and a secondary
transfer section 54. The intermediate transfer belt 52 of an
endless shape extends under tension between the drive roller 50 and
the driven roller 51. The four intermediate transfer rollers 53 are
disposed to face the four photoreceptors 11 through the
intermediate transfer belt 52. The secondary transfer section 54 is
disposed to face the drive roller 51. The secondary transfer
section 54 is constituted to include an endless transfer belt 55
extended between a transfer belt drive roller and two transfer belt
driven rollers, and a secondary transfer roller 56 disposed to face
the driven roller 51 through the transfer belt 55.
[0086] The transfer bias of the polarity reversed from that of the
toner is applied to the intermediate transfer rollers 53 and the
secondary transfer roller 56. The toner image, as formed on the
surface of the photoreceptor 11, is transferred to the surface of
the intermediate transfer belt 52. The toner images, as formed with
the individual toners of the yellow, magenta, cyan and black
colors, are sequentially superposed and transferred onto the
intermediate transfer belt 52 thereby to form a full-color toner
image. The toner image, as formed on the intermediate transfer belt
52, is transferred onto the sheet of recording paper, as
transferred at the adjusted timing between the driven roller 51 and
the secondary transfer roller 56, by the secondary transfer section
54 acting like that intermediate transfer belt 52.
[0087] The cleaning section 17K, as shown in FIG. 2, is constituted
to include a cleaning blade and a toner reserving container. The
cleaning blade is a member for removing the toner residing on the
surface of the photoreceptor 11K, after the toner image on the
surface of the photoreceptor 11K was transferred to the
intermediate transfer belt 52. The cleaning blade is pressed onto
the surface of the photoreceptor 11K by a pressure mechanism (not
shown) thereby to scrape out the residual toner on the surface of
the photoreceptor 11K. The toner reserving container temporarily
reserves the toner scraped out by the cleaning blade. The toner, as
temporarily reserved in the toner reserving container, is discarded
into a waste toner box 57 via a piping (not shown).
[0088] The sheet of recording paper having the toner image
transferred thereto is conveyed to the fixing unit 5 by the
transfer belt 55. The fixing unit 5 is constituted to include a
heating roller heated to a predetermined temperature, and a
pressure roller 5b pressed against the heating roller 5a. The sheet
of recording paper having the toner image transferred thereto is
heated and pressed, while passing through a nip portion formed by
contact between the heating roller 5a and the pressure roller 5b
under pressure, so that the sheet of recording paper has the toner
image fixed thereon. The sheet of recording paper thus fixed is
discharged to the paper discharge unit 6 by the not-shown paper
discharge roller.
[0089] The paper feeding unit 4 is constituted to include a paper
feeding cassette, a pickup roller and a plurality of sets of
registration rollers. The paper feeding cassette houses the sheets
of recording paper. The pickup roller feeds the sheets of recording
paper one by one to a sheet transfer passage. The plurality of sets
of registration rollers feed the sheet of recording paper to a
transfer position or an abutment position, at which the
intermediate transfer belt 52 and the secondary transfer roller 56
abut through the transfer belt 55, when the toner image on the
intermediate transfer belt 52 is transferred to that transfer
position. In the paper feeding unit 4, the sheets of recording
paper, as housed in the paper feeding cassette, are fed one by one
to the paper transfer passage by the pickup roller so that the
sheet of recording paper is fed by the plural sets of registration
rollers to the transfer position between the intermediate transfer
belt 52 and the secondary transfer roller 56.
[0090] The whole actions relating to the image formation by the
image forming apparatus 1 are briefly described in the following.
For example, the image information, as read out by the image
information reading unit 2, of the document is sent to and
graphically processed by the image processing unit. The image
information thus processed is fed to the exposure unit 13, in which
the surface of the photoreceptor 11 charged to the uniform
potential by the charger 12 is exposed to light so as to form the
electrostatic latent image. This electrostatic latent image thus
formed on the surface of the photoreceptor 11 is developed by the
developing section 14 so that the toner image is formed on the
surface of the photoreceptor 11.
[0091] At the transfer unit 16, the toner images, as formed on the
surfaces of the photoreceptors 11 for the individual colors, are
laminated and transferred in the order of the yellow toner image,
the magenta toner image, the cyan toner image and the black toner
image to the intermediate transfer belt 52 so that the full-color
toner image is formed. After the toner images were transferred to
the intermediate transfer belt 52, the toner, as might otherwise be
left on the surfaces of the photoreceptors 11, is removed by the
cleaning section 17. The full-color image, as formed on the
intermediate transfer belt 52, is transferred to the sheet of
recording paper being transferred between the driven roller 51 and
the secondary transfer roller 56.
[0092] The sheet of recording paper having the toner image
transferred thereto is passed through the nip portion between the
heating roller 5a and the pressure roller 5b at the fixing unit so
that the toner image is fixed. The sheet of recording paper having
the fixed image is discharged to the paper discharge unit 6 so that
the series image forming actions are ended.
[0093] In this procedure of image forming actions, the motor 9 for
rotating the toner cartridge 8 of the color is activated by the
control section 7, when the toner density for that color in the
developer container 15 reduces, thereby to supply the developer
container 15 with that toner.
[0094] Here, it is assumed that the developer container 15 to be
supplied with the toner is the developer container 15K for the
black image to be supplied with the toner from either of the two
toner cartridges 8K1 and 8K2. In response to the toner remaining
amount detection information transmitted to the communication
device 48, the control section 7 drives either of the motor 9K1 and
the motor 9K2 so that the toner may be supplied from the toner
cartridge 8 having the less toner remaining amount.
[0095] As a result, the toner can be preferentially supplied from
the toner cartridge 8 of the least toner remaining amount to the
developer container 15. Even in case, therefore, the toner
cartridge before the end of use is employed at the time of
replacement in place of an unused toner cartridge, for example, the
toner cartridge before the end of use and to be earlier used can be
preferentially employed without interrupting the image forming
actions. This makes it possible to prevent the toner cartridge
before the end of use from being degraded in the charging
characteristics and fluidity of the toner, as might otherwise be
caused after left unused for a long time, so that an image of high
quality can always be formed.
[0096] The image forming apparatus 1 thus far described can be
modified in various manners without being limited to the foregoing
constitutions.
[0097] In this embodiment, the accumulated value of the number of
rotations is transmitted as the toner remaining amount detection
information from the wireless IC tag 27 to the control section 7 so
that the remaining amount of the toner is calculated in the control
section 7 from that accumulated value of the number of rotations.
That is, the control section 7 serves as a remaining amount
calculating section. However, the invention should not be limited
thereto but may be modified such that the toner remaining amount is
calculated in the wireless IC tag from the accumulated value of the
number of rotations by Equation (1) and such that the calculated
result is transmitted as the toner remaining amount detection
information to the control section 7. That is, the wireless IC tag
serves as the remaining amount calculating section. In the case of
this modified constitution, the wireless IC tag used is prestored
with both the initial value of the toner quantity to be stored at
the time of manufacturing the toner cartridge and the toner
discharge for one rotation of the toner cartridge 8, and further
includes a remaining amount calculating section for calculating the
remaining amount of the toner to be contained in the toner
cartridge, from the accumulated value of the number of rotations,
as detected by the rotating meter 44, of the toner cartridge.
[0098] Moreover, the toner remaining amount detecting section for
detecting the remaining amount of the toner cartridge 8 should not
be limited to the constitution using the wireless IC tag as the
wireless transmitting/receiving section, but may be modified such
that the toner remaining amount detection information is
transmitted to the control section by a wired
transmitting/receiving section. However, the employment of the
wireless IC tag which is the wireless transmitting/receiving
section, as described in this embodiment, is preferred, because the
arrangement of the toner cartridge and the control section can be
freely set to spare the space for the apparatus.
[0099] Moreover, the toner remaining amount detecting section
should not be limited to the wireless IC tag belonging to each
toner cartridge, i.e., the wireless IC tag having the IC chip unit
which is the nonvolatile memory.
[0100] The constitution, in which the toner cartridge is not
equipped with the wireless IC tag, is exemplified such that a toner
weight sensor is used as the toner remaining amount detecting
section. This toner weight sensor as the toner remaining amount
detecting section is so disposed below each of the toner cartridges
as to detect the weight of the toner cartridge. Moreover, the
control section is prestored with the weight of the container of
the toner cartridge. The weight, as detected by the toner weight
sensor, of the toner cartridge is inputted to the control section
by wired or wireless connections. This constitution can detect the
remaining amount of the toner in the toner cartridge from both the
detection result of the toner weight sensor and the prestored
weight of the container of the toner cartridge.
[0101] Another constitution, in which the toner cartridge is not
equipped with the wireless IC tag, is exemplified by using a
position sensor as the toner remaining amount detecting section. In
the image forming apparatus thus constituted, a spring member is
arranged below each toner cartridge so that the toner cartridge is
disposed on the spring member. When the toner cartridge is charged
with the toner, the toner cartridge is sunk by the weight of the
toner while compressing and deforming the spring member. As the
toner is consumed the more, the entire weight of the toner
cartridge becomes the lighter so that the position of the toner
cartridge is displaced upward by the repulsive force, i.e., the
elongating deformation of the spring member. Moreover, this image
forming apparatus is equipped as the toner remaining amount
detecting section with a position sensor for detecting a
displacement amount of the toner cartridge which is displaced in
position with the change in the remaining amount of the toner
contained in the toner cartridge. At the same time, table data is
stored in the control section in advance. In the table data, the
displacement amount of the toner cartridge which amount is detected
by the position sensor, and the remaining amount of the toner in
the toner cartridge are associated with each other. The
displacement amount of the toner cartridge which amount is detected
by the position sensor , is inputted to the control section by
wired or wireless connections. In this constitution, the remaining
amount of the toner in the toner cartridge can be detected from the
displacement amount of the toner cartridge.
[0102] The invention may be embodied in other specific forms
without departing from the spirit or essential characteristics
thereof. The present embodiments are therefore to be considered in
all respects as illustrative and not restrictive, the scope of the
invention being indicated by the appended claims rather than by the
foregoing description and all changes which come within the meaning
and the range of equivalency of the claims are therefore intended
to be embraced therein.
* * * * *